Since a combustor such as a gas turbine or the like is exposed to a combusted gas having a high temperature, a liner surrounding a combustion region should be cooled. As a means for cooling a combustor liner, an impingement cooling type is provided. In this type, a liner wall is provided as a dual wall structure of an inner wall section and an outer wall section, and a plurality of impingement cooling holes are formed at the outer wall section. Accordingly, using a differential pressure between the inside and the outside of the combustor, a cooling gas is injected toward and collides with the inner wall section from the impingement cooling holes. As a result, the inner wall section exposed to the combusted gas having the high temperature can be cooled.
In addition, as the means for cooling the combustor liner, an effusion cooling type is provided. In this type, a plurality of effusion cooling holes are formed in an inner wall section. Accordingly, in addition to convection cooling by a cooling gas passing through a dual wall, the cooling gas is discharged to a combustion region from the effusion cooling hole. As a result, a gas film is formed at a surface of the inner wall section exposed to the combusted gas having the high temperature, and the inner wall section can be cooled.
Further, in the following Patent Document 1, a combustor liner having a dual wall cooling structure in which the impingement cooling type and the effusion cooling type are combined is disclosed. The combustor liner is characterized in that a cooling gas is discharged to a combustion region in a honeycomb shape, and includes an inner wall section constituted by a plurality of inner wall forming members having regular hexagonal shapes, and an outer wall forming member joined with the inner wall forming members via a joining member having a predetermined shape and configured to support the inner wall forming members. Joining of the joining member to the inner wall forming members and the outer wall forming member is performed by diffusion welding.